1.先建立一個maven主專案，file->new->project，選擇Maven，next


2.建立Eureka服務端，在建立好的maven專案裡面右鍵專案名，new->module，選擇Spring Initialzr，next



然後next再finish，建立完成後pom.xml檔案如下

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 

	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>

	<groupId>com.test</groupId>
	<artifactId>eureka-server</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging
 
>

	<name>eureka-server</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.1.0.RELEASE</version>
		<
 
relativePath/> <!-- lookup parent from repository -->
	</parent>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
		<java.version>1.8</java.version>
		<spring-cloud.version>Greenwich.M1</spring-cloud.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>

	<dependencyManagement>
		<dependencies>
			<dependency>
				<groupId>org.springframework.cloud</groupId>
				<artifactId>spring-cloud-dependencies</artifactId>
				<version>${spring-cloud.version}</version>
				<type>pom</type>
				<scope>import</scope>
			</dependency>
		</dependencies>
	</dependencyManagement>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

	<repositories>
		<repository>
			<id>spring-milestones</id>
			<name>Spring Milestones</name>
			<url>https://repo.spring.io/milestone</url>
			<snapshots>
				<enabled>false</enabled>
			</snapshots>
		</repository>
	</repositories>
</project>

在EurekaServerApplication.java裡面新增@EnableEurekaServer

package com.test.eurekaserver;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;

@EnableEurekaServer
@SpringBootApplication
public class EurekaServerApplication {
	public static void main(String[] args) {
		SpringApplication.run(EurekaServerApplication.class, args);
	}
}

application.properties檔案新增

server.port=8761
eureka.instance.hostname=localhost
eureka.client.register-with-eureka=false
eureka.client.fetch-registry=false
eureka.client.service-url.defaultZone=http://${eureka.instance.hostname}:${server.port}/eureka/

然後啟動專案，在瀏覽器位址列輸入：localhost:8761

這裡顯示No instances available是因為還沒有服務註冊上去
3.建立Eureka客戶端，過程與服務端類似。

建立好後在EurekaClientApplication.java裡面新增@EnableEurekaClient

package com.test.eurekaclient;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

@EnableEurekaClient
@SpringBootApplication
public class EurekaClientApplication {
	public static void main(String[] args) {
		SpringApplication.run(EurekaClientApplication.class, args);
	}
}

然後在EurekaClientApplication.java所在包或所在包的子包下建立HelloController.java

package com.test.eurekaclient;


import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HelloController {
    @Value("${server.port}")
    String port;
        
    @RequestMapping("/hello")
    public String home(@RequestParam String name) {
        return "hello "+name+",i am from port:" +port;
    }
}

最後配置檔案application.properties

spring.application.name=service-hi
server.port=8762
#指向註冊中心，http://${eureka.instance.hostname}:${server.port}/eureka/
eureka.client.serviceUrl.defaultZone=http://localhost:8761/eureka/

然後啟動專案，發現在localhost:8761上面有了服務註冊上去，名稱為service-hi

然後瀏覽器訪問localhost:8762/hello?name=hello即可呼叫服務